This invention relates to the testing of electric components having wound coils, and more particularly, to the use of a device which supplies a high frequency surge to test wound coils for such defects as shorts between coils, shorts between turns of the same coil, and defects found in the wires that form coils.
The manufacturing process for wound coil devices typically has many quality control steps to ensure that a satisfactory product is produced. One well known procedure for determining various defects in wound coils is called the "surge test". It is frequently desired that this test be conducted rapidly, but with precision, on each coil of a particular device to determine the overall quality of the device (e.g. coils of an armature connected to the bars of a commutator or coils of a stator connected to the terminals of an end mold).
Heretofore, the surge test has only had the capability to determine defects such as a short between coils in a winding or a short between turns on the same coil. If a defect has been introduced into the wire as part of the manufacturing process, such as a microfracture in the insulation material, it will not be found by the current surge test. Such defects can lead to precocious degradation of the coil and should be identified before incorporation into the final product.
In view of the foregoing, it is an object of this invention to provide an improved surge test to identify additional defects which can occur during the manufacturing of wound coil devices.